因为|m-2|+(3-3n)^2=0,左式求和的两项都是非负的,和为0,说明二者都等于0.
所以m=2,n=1.
2x^(m-n+1)y^3-6y^(m+n)x^2
=2x^(2-1+1)y^3-6y^(2+1)x^2
=2x^2y^3-6y^3x^2
=-4x^2y^3